Preparation of hydroperoxides

ABSTRACT

ACYCLIC OR CYCLIC METHYL SUBSTITUTED TRISUBSTITUTED OLEFINS TREATED WITH TRIARYLPHOSPHITE-OZONE ADDUCTS YIELD A-METHYLENE HYDROPEROXIDES.

I 3,751,477 PREPARATION OF HYDROPEROXIDES Donald L. Roberts,Winston-Salem, N.C., assignor to R. J. Reynolds Tobacco Company,Winston-Salem, NC. No Drawing. Filed Mar. 13, 1969, Ser. No. 807,072Int. Cl. C07c 49/43 US. Cl. 260-586 B 6 Claims ABSTRACT or run mscLosunnAcyclic or cyclic methyl substituted trisubstituted olefins treated withtriarylphospbite-ozone adducts yield a-methylene hydroperoxides.

This invention relates to organic syntheses and more particularly to thetreatment of acyclic or cyclic methyl substituted trisubstitutedolefins. It is known that triarylphosphites react with ozone .at lowtemperatures to form adducts. For example, the reaction of ozone withtriarylphosphites to form adducts is discussed by Quenton E. Thompson inthe Journal of the American Chemical Society, 83, 845-851 (1961).Triarylphosphite-ozone adducts can be prepared by contacting atriarylphosphite, preferably. dissolved in a suitable solvent, withozone at temperatures below 1-40 .C. Suitable solvents for carrying outthe adduct formation are halogen-containing hydrocarbon solvents such asmethylene chloride, chloroform, trichlorofluoromethane,dichlorodifluoromethane and the like.

It has now been found that triarylphosphite-ozone adducts when utilizedto treat trisubstituted olefins yield substantially exclusively allylichydroperoxides which, among others, find use as chemical intermediates.An unexpected feature of this discovery is the fact that thetriarylphosphite-ozone adducts, when utilized to treat methylsubstituted trisubstituted olefins, produce almost exclusively oneproduct, namely a-methylene alkyl hydroperoxides, in contrast to themixture of products usually produced by treating trisubstituted olefinswith a source of singlet oxygen such as oxygen produced byphotosensitization or by reaction of a hypochlorite and hydrogenperoxide.

This specificity for ear-methylene alkyl hydroperoxide formation isshown by data in Table 1: g I v TABLE 1 United States Patent "ice3,751,477 Patented Aug. 7, 1973 tene, dipentene, l-p-menthene,l-m-menthene, o-m-menthene, 2-pinene, Z-careue, 3-carene, a-cedrene,l-methylcycloheptene, 2(4-methylcyclohex-3'eml-yl)-6-methylheptan-4-one, lx-terpineol,caryophyllene and the like.

The syntheses of this invention are carried out by contacting a saidolefin, preferably dissolved in an inert solvent, with atriarylphosphite-ozone adduct. This treatment can be conducted in anysuitable equipment at temperatures ranging from C. to 10 0., preferably40 to 20 C. for periods ranging from 0.5 to 24 hours. Inert solventssuitable for carrying or dissolving the olefins include, for example,chloroform, methylene chloride, carbon tetrachloride, pentane, hexane,cyclohexane, petroleum ethers and the like.

The hydroperoxides formed by treating the olefins with atriarylphosphite-ozone adduct are generally reduced by conventionalmeans to allylic alcohols without separation from the reaction mixture.Such conventional reductive reagents as triphenylphosphine, triethylphosphite, sodium borohydride, potassium iodide, sodium sulfite andlithium aluminum hydride can be employed for this purpose Alternatively,the so-formed hydroperoxides can be converted to a s-unsaturated ketonesby treatment with bases such as, for example, sodium hydroxide,potassium hydroxide, barium hydoxide, sodium carbonate, alumina, etc.

Representative triarylphosphites which can be reacted with ozone to formadducts include, for example, triphenylphosphite, tris(p-tolyl)phosphite, tris-(p-butylphenyl)phosphite,tris-(p-methoxyphenyl)phosphite, tris- (p-chlorophenyl)phosphite, tris-(p-nitrophenylllphosphite, tris (p aminophenyDphosphlte,tris-(p-t-butylphenyl) phosphite, tris-(m-ethylphenyl)phosphite,tris-(p-fiu0ro phenyl) phosphite and tris-(2,4-dimethylphenyl)phosphite.

The following examples illustrate the present invention.

EXAMPLE I Triphenylphosphite (15.5 g., 13 ml., 0.05 mole) was dissolvedin 100 milliliters of methylene chloride and the solution was cooled tobelow -50 C. Ozone was bubbled into the cooled solution until 0.05 moleof ozone was Yields by methods, percent Hypo- Photochlorite Phosphitesensitized peroxide, Olefin Products 1 ozone oxygenation percent awn-33-pln -2 1 pinen-lO-ol...

l Elle products were alcohols obtained by reduction of thehydroperoxldes and analyzed by gas chromatograp The olefins which aretreated with thetriarylphosphiteozone adducts to form hydroperoxides inaccordance with absorbed as was indicated by the blue-green color of thesolution. The excess ozone in the solution was purged with nitrogen.

The procedure of this example was employed for prepa- 7 ration of thephosphite-ozone reagents utilized in obtaining the data summarized inTable 1.

EXAMPLE II Following the procedure of Example I, the'followirfgsubstituted arylphosphite-ozone adducts were prepared:

Tris- (p-tolyl)phosphite Tris- (p-butylphenyDphosphite Tris-(p-methoxyphenyl) phosphite Tris- (p-chlorophenyl) pho sphite EXAMPLEIII Following the procedure of Example I,tris-(p-nitrophenyl)phosphite-ozone adduct was prepared using one tenththe concentration of the phosphite.

EXAMPLE IV Following the procedure of Example I, triarylphosphite-ozoneadducts are prepared using as solvents chloroform,trichlorofluoromethane and dichlorodifluoromethane.

EXAMPLE V EXAMPLE VI To a cold (70 C.) solution oftriphenylphosphiteozone adduct was added 15.4 grams of geraniol in 25milliliters of methylene chloride. The solution was warmed to 30 C. for3 hours, then the cooling baths were removed. After standing overnightthe material was reduced with triphenylphosphine and then distilled.11.18 grams of geraniol was recovered along with 2.10 grams of a productwhich was shown by nuclear magnetic resonance spectrum to be3-methylene-7-methyl-6-octene- 1,2-diol.

EXAMPLE VII A solution of 20 grams of tris-(p-methoxyphenyl)phos- '5qphite in 100 milliliters of methylene chloride'was cooled to 50 C. Ozonewas bubbled into the cooled solution until 0.05 mole of ozone wasabsorbed. I Fourteen grams of limonene in 25 milliliters of methyl-' enechloride was added slowly to a cold solution (-70 C.) of thetris-(p-methoxyphenyl)phosphite-ozone ad'- duct. After warming to roomtemperature overnight the I hydroperoxide was reduced and the solutiondistilled.

Eleven grams of limonene were recovered in addition to. v

0.73 gram of 1(7),8-p-menthadien-2-ol which was identified by infraredand nuclear magnetic resonance spectra.

EXAMPLE VIII The procedure of Example VII was repeated using an ozoneadduct from 1 gram of tris-(p-nitrophenyl)phosphite in 150 millilitersof methylene chloride a'ntljl grain of limonene. Gas chromatographicanalysis'showed the production of 1(7),8-p-menthadien-2-ol inapproximately 10% yield.

EXAMPLE IX The product 1(7),8-p-menthadien-2-ol produced as in ExamplesVII and VIII can be converted to 'perillaldehyde which can then beconverted to perillartine which thereof.

finds use as a synthetic sweetener. These conversions are illustrated bythe.following.reactiont.v

(IJH Cf-Ho CH=NOH OH I :1 1' e f CH3 CHI 0E \CHQ, 0E3 \CH: 1(7),8pmenthadlen2ol Perillaldehyde Pe'rlllartlne Step l in the abovereaction isi accomplished by the use of chromic acid-sulfuric acidreagent according to the procedure of F. Porsch reported inDragoco-Reports, 149-152 (196.4).. Y I In Step 2, the perillaldehyde isconverted to the: oxime by known procedure as, for example, theprocedure reportedin ChemicalAbstracts, 14, 2528 (1920).

. EXAMPLE X I To the ozone adduct from 21 grams oftr'is-(p-chlorophenyl)phosphite in milliliters of methylene chloride wasadded 20 grams'of' a-cedrene in 25 milliliters of methylene chloride ata temperature of-50 C. After warming to room temperature, themixture'was reduced with triphenylphosphine. Gas chromatographicanalysis 'followedby distillation showed'a '5% conversion of a-c'edreneto cedr-8(15)-en-9ot-ol. The product crystallized from acetone andhexane and melted at 128 (reported melting point 129.5).

XAMPLE XI Following the procedure of Example X, atriphenylphosphite-ozone' adduct was employed to treat a-cedrene. Thistreatment resulted in a 23% conversion of a-cedrene and a 50%*yie1dof'cedr-8 (15 -en-9a-ol.

,,. n EXAMPLE XII The -c'edr-8( 15 -en- 9wol can be -oxidized using Iehrornic oxide to the corresponding aldehyde'which in turn can beoxidized using silver oxide to 1 cedrene' carboxylic acid which findsuse as a plant'gro'w'th' stimulator. These conversion's'are' illustratedby the following:

and Silver oxide n l....- i I CH1 Oedren a .carboxyllc acidThosemodifications and-equivalents which ran within the spirit of theinvention are to be considered apart 'I claim: y 5 e "m .A pro'cessforipreparing an'a-methylenealkyl hydroperoxide-1whichbomprisestreating' witha tria-rylphosphiteozone-adduct=in1an inert solventata'temperature in the ran e of. .-60; 6.: to,.;109 C. a methylsubstituted trisub- -stitutedrolefin selected from theagroup consistingof 2- methyl-Z-bntene, Z-methyl-Z-pentene, 3-methyl-2-pentene,Z-methyI-Z-hexene, 2,5-dirnethyl-2-hexene, 2,4-dimethy1- 2-pentene,geraniol, farnesol, l-methylcyclohexene, 1- methylcyclopentene,dipentene, l-p-rnenthene, l-m-menthene, 6-m-rnenthene, Z-pinene,IZ-carene, 3-carene, acedrene, l-methylcycloheptene,2-(4-methylcyclohex-3-enl-yl)-6-methy1heptan-4-one, a-terpineol andcaryophyllene.

2. A process in accordance with claim 1 wherein atriphenylphosphite-ozone adduct is employed.

3. A process in accordance with claim 1 wherein atris-(p-methoxyphenyl)phosphite-ozone adduct is employed.

4. A process in accordance with claim 1 wherein atris-(p-nitrophenyl)phosphite-ozone adduct is employed,

5. A process in accordance with claim 1 wherein atris-(p-chlorophenyl)phosphite-ozone adduct is employed.

6. A process in accordance with claim 1 wherein the inert solvent isselected from the group consisting of seturated hydrocarbons andsaturated halogenated hydrocarbons.

References Cited UNITED STATES PATENTS 3,061,646 10/1962 Bartols260'--610 B 3,502,740 3/1970 Zajacek ct a1 260-610 B 3,510,537 5/1970Sheng et a1 260610 B OTHER REFERENCES Thompson, J. Amer. Chem. Soc.,vol. 183 (1961),

U.S. C1. X.R.

260610 B, 598, 514 B, 593 R, 566 A, 617 C, 632 R, 635 R, 631.5

